• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.581-586
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• 2011

'Cheongdam' is a japonica rice variety developed from a cross between SR19200-HB826-34, a line of good germination ability and shoot emergence at low temperature and Juanbyeo, good quality and direct-seeding adaptable cultivar by the rice breeding team of National Institute of Crop Science, RDA in 2006. This variety has 153 days of total growth duration from seeding to maturity in direct-seeding, and 160 days of growth duration from seeding to maturity in transplanting. This is erect plant type with culm length of 74 cm, thick culm, and green leaves. It has large panicle shape with 126 and 140 spikelets per panicle in direct-seeding and transplanting, respectively. Milled rice is transluscent and medium in grain size of non-glutinous endosperm. This variety is susceptible to leaf and neck blast, bacterial blight, stripe virus disease and brown planthopper. The yield potential of 'Cheongdam' is 5.84 MT/ha at ordinary transplanting culture and 5.62 MT/ha and 5.89 MT/ha at wet direct-seeding and dry direct-seeding cultures, respectively in the local adaptability test for three years. 'Cheongdam' would be adaptable to middle and southern plain of Korea for direct-seeding culture and transplanting rice culture.

• Korean Journal of Breeding Science
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• v.43 no.3
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• pp.190-195
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• 2011

'Youho' (Hordeum vulgare L.), a new ruminant-palatable forage barley cultivar, was developed by the breeding team at the Department of Rice and Winter Cereal Crop, National Institute of Crop Science, RDA in 2008. It was derived from the cross between 'Suwon339' and 'Suwon355'. Among the cross made in 1999, a promising line, SB992047-B-B-B-6-2, showed good characteristics in potential forage yield in the yield trial tested at Iksan from 2005 to 2006. In 2007, it was designated as 'Iksan431' and placed in regional yield trials at eight locations in Korea for two years from 2007 to 2008, and was released as the name of 'Youho'. It has the growth habit of group II, erect plant type, green leaf and hood spike. Its average heading and maturing dates were on Apr. 24 and May 26, respectively, which are similar to check cultivar 'Yuyeon'. 'Youho' also showed weaker winter hardiness, but better resistance to lodging, shattering and BaYMV than those of check cultivar. It showed higher crude protein content, grade of silage quality than those of check cultivar. The average forage dry matter yield in the regional yield trial was about 14.1, $10.9MT\;ha^{-1}$ in upland and paddy field, respectively, which were 1% to 4% lower than that of the check cultivar. This cultivar would be suitable for the area whose daily minimum temperature was above $-8^{\circ}C$ in January in Korean peninsula.

• Korean Journal of Breeding Science
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• v.41 no.2
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• pp.177-181
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• 2009

'Pyeongwon' is a new japonica rice cultivar which is developed from a cross between Jinbu19 and Samjiyeon4 from North Korea by the rice breeding team of National Institute of Crop Science, RDA. Pyeongwon has about 107 days duration from seeding to heading in mid-northen plain, alpine, north-eastern coastal and southern alpine areas. It has about 67 cm culm length and tolerance to lodging. Pyeongwon has 13 tillers per hill and 82 spikelets per panicle. It showed tolerance to heading delay and spikelet sterility due to cold treatment similar to Odaebyeo. It also showed slow leaf senescence and moderate tolerance to viviparous germination during the ripening stage. Pyeongwon has resistance to blast disease but susceptible to stripe virus and brown planthopper. Milled rice of Pyeongwon has translucent kernels, relatively clear non-glutinous endosperm and medium short grain. It is characterized as a low gelatinization temperature and slightly lower amylose content (17.1%) variety compared to Odaebyeo (19.5%) and has good palatability of cooked rice. The milled rice yield performance of this cultivar was about 5.28 MT/ha by ordinary culture in local adaptability test for three years. This cultivar may be highly adaptable to the mid-northen plain, alpine, north-eastern coastal and southern alpine areas of Korea.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.4
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• pp.253-259
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• 2018

A new barley (Hordeum vulgare L.) cultivar 'Mihan' having ruminant-palatable semi-smooth awn and good silage quality was developed at National Institute of Crop Science(NICS), RDA in 2016. This cultivar was derived from a cross of the 'SB00T2064' and 'Suwon385' in 2001. And its promising line showed high yielding through the preliminary yield trials(PYT) and advanced yield trials (AYT) in Iksan from 2012 to 2013. It was designated as the 'Iksan487'. 'Iksan487' was conducted to regional yield trials (RYT) in one upland field and five paddy fields around Korea for three years from 2014 to 2016. And it was released as the name of 'Mihan'. It has growth habit of IV, erect plant type, green leaf and semi-smooth awn. Its heading date was April 23 in the paddy field and maturing date was May 24. Plant height of 'Mihan' was 96cm. Mihan's spikes per $m^2$ was 665. It has better winter hardiness and resistance to BaYMV (Barley Yellow Mosaic Virus) than that of barley cultivar 'Youngyang'. The average dry matter of 'Mihan' was about $10.9ton\;ha^{-1}$ in paddy field. And average feed quality of 'Mihan' was 10.3% of crude protein content, 26.1% of ADF (Acid Detergent Fiber), 46.9 % of NDF (Neutral Detergent Fiber) and 68.2% of TDN (Total Digestible Nutrients). 'Mihan' had grade I of silage quality. This cultivar would be suitable for the area above the daily minimum average temperature of $-8^{\circ}C$ in January in Korean peninsula.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.198-221
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• 2021

After large-scale reforestation in the 1960s and 1970s, forests in Korea have gradually been aging. Net ecosystem CO₂ exchange of old-growth forests is theoretically near zero; however, it can be a CO₂ sink or source depending on the intervention of disturbance or management. In this study, we report the CO₂ budget dynamics of the Gwangneung deciduous old-growth forest (GDK) in Korea and examined the following two questions: (1) is the preserved GDK indeed CO₂ neutral as theoretically known? and (2) can we explain the dynamics of CO₂ budget by the common mechanisms reported in the literature? To answer, we analyzed the 15-year long CO₂ flux data measured by eddy covariance technique along with other biometeorological data at the KoFlux GDK site from 2006 to 2020. The results showed that (1) GDK switched back-and-forth between sink and source of CO₂ but averaged to be a week CO₂ source (and turning to a moderate CO₂ source for the recent five years) and (2) the interannual variability of solar radiation, growing season length, and leaf area index showed a positive correlation with that of gross primary production (GPP) (R²=0.32~0.45); whereas the interannual variability of both air and surface temperature was not significantly correlated with that of ecosystem respiration (RE). Furthermore, the machine learning-based model trained using the dataset of early monitoring period (first 10 years) failed to reproduce the observed interannual variations of GPP and RE for the recent five years. Biomass data analysis suggests that carbon emissions from coarse woody debris may have contributed partly to the conversion to a moderate CO₂ source. To properly understand and interpret the long-term CO₂ budget dynamics of GDK, new framework of analysis and modeling based on complex systems science is needed. Also, it is important to maintain the flux monitoring and data quality along with the monitoring of coarse woody debris and disturbances.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.489-495
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• 1996

Seedling emergences of four rice varieties (Dongjinbyeo, Dadajo, Galsaekggarak-sharebyeo, and Italiconaverneco) and three barnyardgrass species(Echjnochloa oryzjcola, E. crus-gali var. crus gali E. crus-gali var. praticola) were evaluated in relation to soil strength. Soil strength was varied by compressing the entire volume of soil with a hydraulic jack so as to be 0.5, 1, 2, 3, 6kg /$\textrm{cm}^2$. Soil strength was measured with a penetrometer (Yamanaka type) and soil covering above the seed was 4cm deep. Experiments were conducted at two air temperature conditions of 17 and $25^{\circ}C$. At a soil strength of up to 2kg/$\textrm{cm}^2$, little or no decrease in seedling emergence occurred in all rice varieties and barnyardgrasses tested. Above that value, seedling emergence decreased progressively as the soil strength increased. The degree of decrease was greatest in Dongjinbyeo and smallest in Dadajo among tested rice varieties, and greatest in Echinochloa oryzicola among barnyardgrasses, being greater in barnyardgrasses than rice. Seedling emergence was delayed almost linearly as the soil strength increased. The delay was greatest in Dongjinbyeo among rice varieties and in Echinochloa oryzicola among barnyardgrasses. Mesocotyl length increased as soil strength increased up to 2 to 3kg / $\textrm{cm}^2$ in Dongjinbyeo and Dadajo in 17$^{\circ}C$ and $25^{\circ}C$, and up to 6kg/$\textrm{cm}^2$ in Galsaekggaraksharebyeo and Italiconaverneco in $25^{\circ}C$. Dongjinbyeo showed the least elongation of mesocotyl among rice varieties in any soil strength. The total length of mesotyl, first internode and incomplete leaf showed little variation with soil strength. The total length was longer than the 4cm covering depth in other varieties except Dongjinbyeo. This might have caused the lower emergence rate in Dongjinbyeo than other varieties in higher soil strength.